Our research objective is to develop procedures to rehabilitate those stroke patients who, through conventional therapies, were not brought to a level of maximal recovery. The aim of the study is to obtain a set of data from a total of 16 chronic stroke subjects, all with lower extremity disability, between the ages of 18-75, using the AMES robotic device in a rehabilitation clinic. Each subject will participate in 10 weeks of therapy, 3 days per week, 30 minutes per day. The data collected will be analysed to quantify the extent to which a combination of robot-assisted exercise and muscle vibration induce secondary recovery from stroke in the lower extremity.